A dossier of abuse of the human rights of children and young people in Britain will be presented to United Nations inspectors today in a joint submission from the four children's commissioners for England, Scotland, Wales and Northern Ireland.

They will report widespread infringements of the UN convention on the rights of the child (UNCRC) that have denied hope and opportunity to many of Britain's 14 million children and adolescents. The most serious defects include:

· A punitive juvenile justice system;

· Public attitudes that demonise teenagers;

· Lack of protection against physical punishment in the home;

· One of the highest levels of child poverty in Europe.

The commissioners will submit their complaints to a UN review of children's rights in Britain, which is due to examine whether any improvements have been made over the past five years. In a report in 2002, the UN committee on the rights of the child accused the government of "serious violations" including failure to ban parental smacking, detention of child asylum seekers and use of plastic baton rounds on children in Northern Ireland.

It said children's commissioners should be appointed to uphold young people's rights. This recommendation was accepted - first by the devolved administrations in Scotland, Wales and Northern Ireland and, more recently, by the UK government acting on behalf of England.

But the commissioners said many of the UN's other 77 recommendations were not effectively implemented. "Some things have actually got worse. We would cite developments in juvenile justice and public attitudes towards children as examples of this ... We have continued to pursue the need for a ban on the physical punishment of children, challenging our governments' claims that recent legislative changes have dealt with the matter," they said.

Breaches of the convention included the use of painful thumb holds to control young offenders, plans to use dental x-rays to check the age of child asylum seekers, and institutional discrimination by the NHS against children with learning difficulties.

Sir Al Aynsley-Green, the commissioner for England, said: "Our report clearly highlights areas of major concern where the government and devolved administrations continue to fail to deliver on their promises to our younger generation when they signed the UN convention on the rights of the child 18 years ago."

He complained of a punitive approach to misbehaviour by children and young people. "Compared with other European countries, England has a very low age of criminal responsibility and high numbers of children are locked up ... Around 3.1 million children in England are living in poverty (29%) and more than 1 million children are living in poor housing."

Keith Towler, the commissioner for Wales, said one of the good things about being a child in Wales was the absence of school league tables and tests at seven, 11 and 14. Bad things included the imprisonment of Welsh children in England and children's health services that were not as well funded as adult services.

Patricia Lewsley, the commissioner for Northern Ireland, said racism and discrimination was a common experience for children from Traveller and ethnic minority communities.

Kathleen Marshall, commissioner for Scotland, said that in Scotland children under 16 were less likely to be punished by the courts. "After that age, young people are largely classed as adults for the purpose of criminal justice. Scotland locks up too many young people aged 16 and 17. Scotland shares with the rest of the UK a public attitude towards children and young people that tends to demonise them and often seems to wish to exclude them from public spaces ... Scotland's health record is appalling."

The commissioners will discuss their findings with UN officials in Geneva on Wednesday. They will be accompanied by a delegation of children from across England, who will complain of negative media messages and a lack of respect from adults.

The delegation's demands include giving children more say when their parents separate, reducing exam and coursework pressure, and ensuring children's voices are listened to in schools.

In a further submission, the Children's Rights Alliance for England, a coalition of more than 100 charities, said the government had passed 30 laws since 2002 that breached the UN convention. Carolyne Willow, the national coordinator, said: "Although the government has put children at the heart of its programme, it has failed to protect the most vulnerable."

Children's minister Beverley Hughes said: "We are 100% committed to improving children's wellbeing - over the course of this government more than 600,000 children have been lifted out of poverty, almost 3,000 children's centres have been built and school funding has been increased by 87%.

"However, we are not complacent. The fact that we created a new government department for children, schools and families shows how serious we are about helping families and communities to give their children a happy childhood. Our children's plan is our long-term vision to address many of the issues raised in the UNCRC report."

Pain and prejudice : What the report said

The commissioners identified more than 100 areas in which children's rights should be strengthened. They included

Physical restraint

Thousands of children are imprisoned every year in secure training centres and young offender institutions.

Between January 2004 and September 2005 forcible physical restraint was used on 7,020 occasions. This involved painful nose, rib and thumb holds, described by the authorities as "distraction techniques".

The commissioners said: "On many occasions these techniques have caused injury to children." They welcomed the government's decision to suspend the use of "nose distraction" and called for the outlawing of other violent forms of control or punishment.

"Restraint is not being used only as a last resort and there is evidence that restraint and pain are being routinely used ... as a response to non-compliant behaviour." In 2004, two children died after being restrained.

Smacking

The UN said in 2002 that Britain's refusal to ban physical punishment in the home was a serious violation of children's human rights. Although the law has been changed, parents are still allowed to carry out "reasonable chastisement". This offers little protection to children, who should have the same legal protection against assault as adults, the commissioners said.

Learning disabilities

Across Britain, 82% of children with learning disabilities are bullied and most are afraid to venture out in the street. "There is evidence of institutional discrimination in the NHS against people with a learning disability, leading to neglect and unequal healthcare."

Poverty

The government took measures to remove 600,000 children from poverty between 1998-99 and 2005-06, but subsequently the number of poor children has increased by 200,000. "It is unacceptable that a country as wealthy as the UK has 3.8 million children (one in three) living in relative poverty." The government's strategy was not sufficiently targeted at children at greatest risk, including black and ethnic minority children, asylum seekers and children leaving care.

Education

Children are not asked their views and educational inequalities persist. The system fails to meet the needs of children with special needs and cannot cope with the rising number of children with autism and social, emotional or behavioural difficulties. Only 8% of science GCSE textbooks are available in large print or Braille.

Disability

Half of all families with disabled children are living at or below the poverty line. A quarter of all children with a disabled parent live in poverty. Only 6% of families with disabled children reported being "comfortably off".

Asylum

The commissioners strongly object to a government plan to use dental x-rays to establish the age of asylum applicants. This would be unethical, unlawful and no more accurate than non-invasive methods. They detected a drive to remove children from Britain as soon as an asylum claim has failed.